… We analyze the null geodesic equations in five-dimensional spherically symmetric spacetime with collapsing inhomogeneous dust cloud. … By using a new method, we prove the existence and non-existence of solutions to null geodesic equations emanating from the central singularity for smooth initial distribution of dust. … Moreover, we also show that the null geodesics can extend to null infinity in a certain case, which implies violation of the cosmic censorship conjecture. …

… Cosmicdust measurement has been one of the fundamental investigations of the Solar System exploration and sample returns from low Earth orbit have substituted knowledge gaps of the terrestrial collection of astromaterials. … Exo-planetary system studies now demand deeper understanding of the Solar System dust structure and compositions as templates for all other planetary systems in the Universe. …

… Potential scientific objects include in-situ observation and remote sensing from these space are solar system explorations, such as, the observations of plasma and energetic particles around the terrestrial magnetosphere, inter-planetary and inter-stellar dust, and NEO. … It is also considered to be useful for the pilot observations for future infrared, gamma-ray, and cosmic-ray space astronomical telescope in the deep space. …

… Interplanetary dust particles (IDPs) are most promising carriers of extraterrestrial organic compounds, but presence of bioorganic compounds are controversial since they are so small and were collected in the terrestrial biosphere. … In addition, IDPs are directly exposed to cosmic and solar radiation. …

… Objective of the improvements was to measure ultra-small amounts of noble gases in extraterrestrial materials such as meteorites and cosmicdust particles by using a laser microprobe to extract noble gases. …